BRIDGEPORT, Conn. (AP)  A newly released report reveals witnesses saw an airplane performing acrobatic maneuvers minutes before it crashed in Arizona, killing a former president of a major aircraft manufacturer and another Connecticut man.

The Connecticut Post reports the National Transportation Safety Board released a factual report Wednesday on the 2016 crash that killed the pilot, 61-year-old Jeffrey Pino, and 72-year-old Nicholas Tramontano.

Pino was a former president of Sikorsky Aircraft, a Connecticut-based aircraft manufacturer. Tramontano was a longtime aviator, who also collected vintage aircraft.

While the report did not say if the acrobatic maneuvers led to the crash, it did say the aircraft flight manual prohibits intentional power-on spins or snap rolls. The manual says it is “impossible” to do a good snap roll, and power-on spins are “extremely dangerous.”